Digestive System HS I. What are the structures and functions of the Digestive System? Objective 2.07 & 2.08 Essential questions: What are the structures.

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Presentation on theme: "Digestive System HS I. What are the structures and functions of the Digestive System? Objective 2.07 & 2.08 Essential questions: What are the structures."— Presentation transcript:

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Digestive System HS I

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What are the structures and functions of the Digestive System? Objective 2.07 & 2.08 Essential questions: What are the structures of the digestive system? What are the fxs & disorders of the digestive system?

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Structures of the digestive system Digestive system Also known as: Alimentary Canal Digestive Tract Gastrointestinal Tract Upper GI Lower GI Approximately 30 in length from mouth to anus 3

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1.Physical breakdown of food 2.Chemical digestion of food into the end products of fat, carbohydrates and protein. 3.Absorb nutrients into blood capillaries of the small intestines 4.Eliminate waste products of digestion Functions of the Digestive System

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Structure of Organs of Digestion - Mouth A.K.A. Buccal Cavity Food enters digestive system through mouth Inside of mouth covered with mucous membrane Roof of mouth is HARD PALATE (bone) and SOFT PALATE UVULA – flap that hangs off soft palate – prevents food from going up the nose when you swallow

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Structure of Organs of Digestion - Tongue Attached to floor of mouth Helps in chewing and swallowing Made of skeletal muscle attached to four bones Taste buds on the surface – sweet, sour, bitter, salty

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Structure of Organs of Digestion – Stomach Upper part of abdominal cavity - LUQ CARDIAC SPHINCTER – circular layer of muscle, controls passage of food into stomach from esophagus PYLORIC SPHINCTER – valve, regulates the entrance of food into duodenum RUGAE – mucous coat lining of stomach in folds when the stomach is empty Stomach has muscular coat that allows it to contract (peristalsis) and push food into the small intestine

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Structure of Organs of Digestion – Stomach

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Structure of Organs of Digestion – Small Intestines DUODENUM – first segment, curves around pancreas, 12 long JEJUNUM – next section, 8 ft. long ILEUM – final portion, feet long ABSORPTION – in small intestine, digested food passes into bloodstream and on to body cells, undigestible passes on to large intestine

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Accessory Organs of Digestion - Liver Largest organ in the body Located below the diaphragm, upper right quadrant Connected to gallbladder and small intestine by ducts Functions: Produce and store glucose in the form of GLYCOGEN Detoxify alcohol, drugs and other harmful substances Manufacture blood proteins Manufactures bile Store Vitamins A, D and B complex

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Accessory Organs of Digestion – Gall Bladder Small green organ, inferior surface of the liver Stores and concentrates BILE from the liver until needed by the body When fatty foods digested, bile released by gallbladder for digestion

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CHYME – semi-liquid food Approx 2 in diameter Also called the colon CECUM – lower right portion of large intestine APPENDIX is finger-like projection off cecum RECTUM – last portion of large intestine ANUS – external opening Accessory Organs of Digestion – Large Intestines

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Understand the functions of the digestive system 22

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Digestion BOLUS – soft, pliable ball – creating from chewing and addition of saliva – it slides down esophagus PERISTALSIS – wavelike motions, moves food along esophagus, stomach and intestines In the mouth… saliva softens food to make it easier to swallow PTYALIN in saliva converts starches into simple sugar (maltose) under nervous control – just thinking of food can cause your mouth to water

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Digestion In the stomach… gastric (digestive) juices are released Acid and enzymes Pepsin – enzyme that breakdowns proteins stomach walls churn and mix (This mixture is chyme) small amount of chyme enters duodenum at a time - controlled by pyloric sphincter takes 2-4 hours for stomach to empty

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Digestion In the small intestine… where digestion is completed and absorption occurs addition of enzymes from pancreas and bile from liver/gallbladder Villi – small finger-like projections that protrude from the epithelial lining of intestinal wall – increase surface area of the intestinal wall for increased absorption area

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Digestion In the small intestine-pancreas… enzymes release into the small intestines amylase – breaks down starch steapsin – breaks down fat pancreatic proteases – breaks down proteins

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Functions of the digestive system Fecal transplant Allows the bacteria from the healthy stool to repopulate the gut of the patient who has lost healthy bacteria in their gut Used to treat Clostridium difficile that grows in human intestines Symptoms range from persistent diarrhea to life- threatening inflammation of the colon to death

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What are the characteristics and treatment of common digestive disorders?